There is currently no evidence that estrogen increases the risk of cancer among those in surgical menopause. Several studies have found that taking estrogen in surgical menopause did not affect risk for any cancer, and a few studies have even found a reduced risk of breast cancer with estrogen in surgical menopause.
Studies suggest that this is even true for those who are BRCA1 and BRCA2 positive. You can read more here.
Visit www.iapmd.org/surgery for lots of evidence-based information and resources for those considering, going through or recovering from surgery for PMDD/PME.